Gas generator compositions containing a substituted glyoxime

ABSTRACT

HIGH PERFORMANCE GAS GENERATOR COMPOSITIONS TO BE USED ON BOARD MISSILES TO PROVIDE SECONDARY POWER. AN HYDROXYL-, AMINO-, OR HALOGEN-SUBSTITUTED GLYOXIME IS USED.

United States Patent ()ffice 3,?4l,828 Patented June 26, 1973 ABSTRACT OF THE DISCLOSURE High performance gas generator compositions to be used on board missiles to provide secondary power. An hydroxyl-, amino-, or halogen-substituted glyoxime is used.

'Dedicatory clause.-The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalty thereon.

Background of the invention-This invention relates to gas generator compositions and particularly to high performance gas generator compositions to be used on board missiles to provide secondary power.

Prior art gas generators have consisted mainly of mesaburning double-base propellant compositions, various rubber-ammonium nitrate compositions and hydrazine bisborane. See US. Pat. 3,170,203.

Mesa-burning double-base and rubber-ammonium nitrate gas generator compositions are acceptable for many applications. However, it has been found that their use in rockets whose guidance depends on the transmission of radio or radar signals leads to interference in the signal transmission with a corresponding loss in effective command transmission to and accuracy of the rocket. This is particularly true in military rockets such as air defense weapons whose flight is observed through various tracking means and any needed corrections in the rockets flight are made through electrical or radio signals transmitted to instruments on board the rocket.

These conventional gas generator compositions interfere with the radio or radar signal because of the large particles in the exhaust plume from the burning composition. Water vapor particularly interferes with the signal transmission as do aluminum oxide particles when aluminum is a fuel component. However, any particles larger than about 5 to microns interfere with the signal and should be eliminated if possible.

This has led to the use of hydrazine bisborane or compositions consisting essentially of hydrazine bisborane and a binder to overcome the disadvantages of the conventional gas generator compositions.

However, the exhaust plume from the decomposition of hydrazine bisborane offers some interference to the transmission of radio signals. Conventional mechanical filters are needed to remove the boron nitride particles from the exhaust plume.

In accordance with the foregoing, it is an object of this invention to provide improved gas generating compositions.

A further object of this invention is to provide a gas generating composition, the decomposition products of which leave no particulate matter.

Summary of the invention.-lt has been discovered that either 1,2-dihydroxyglyoxime, 1,2-diaminoglyoxime, 1,2- difluoroglyoxime or other closely related compounds (alone or in conjunction with ammonium nitrate) may advantageously be used in high performance gas generator compositions to be used on board missiles to provide secondary power.

Description of the preferred embodiments-For example, 1,2-dihydroxyglyoxime, on decomposition, undergoes the following reaction:

It is especially important to note that the exhaust products will be completely smokeless with little or no afterburning.

Similarly, 1,2-diarninoglyoxime, on decomposition, undergoes the following reaction:

Thus the initiation of thermal decomposition of these compositions results in lower molecular Weight exhaust products which means higher performance, lower combustion flame temperature, amelioration of. radiometric and radar communication problems through the plasma, etc.

1,2-diaminog1yoxime has been synthesized E. Fisher, Berichte, 22, 1930 (1889); Chemical Abstracts, 52, 51 (1958).

(1,2-diaminoglyoxime can be prepared from the reaction of cyanogen in a solution of hydroxylamine according to the procedure in the first of the above references. The second reference shows how to increase the yield by cooling the reaction mixture, and by using hydroxylamine of high purity. In this manner, only a single recrystallization is necessary to obtain 1,2-diaminoglyoxirne of high purity.)

The other compounds are unreported.

1,2-dihydroxyglyoxime can be prepared by the reaction of an excess of hydrogen peroxide and cyanogen:

(Preferably a 50% excess of the theoretical amount of hydrogen peroxide is employed.)

1,2-difluoroglyoxime can be prepared by the reaction of cyanogen with an acidic solution of sodium hypofluorite:

Examples of the preparation of other closely related compounds follow:

1,2-diaminoglyoxal dihydrazone can be prepared by a procedure analogous to that used for the preparation of 1,2-diaminoglyoxime, starting with hydrazine and cyanogen:

NC: CN+ 2H N.NH

H N.C( :N.NH .C( N.NH .NH 1,2-epoxyglyoxime can be prepared by the reaction of approximately equimolar amounts of hydrogen peroxide and cyanogen:

C:N OH

NCzCN H2O; C

1,2-difluoroglyoxal dihydrazone can be prepared by the reaction of cyanogen with fiuoramine:

No alteration in conventional gas generator apparatus is necessitated by this invention. In its simplest application, all that is required to utilize this invention is to substitute the hydroxyl-, aminoor halogen-substituted glyoxime for the presently used gas generator composition. In one aspect of this invention, the hydroxyl-, aminoor halogen-substituted glyoxime is press-loaded into the fuel chamber of the gas generator hardware using a pressure plate which has a forward projecting cylindrical rod. In this manner a Single cylindrical internal perforation can be produced in the gas generator shaped charge. Of course, a star-shaped internal perforation, or internal perforations of any other desired configuration can be produced by utilizing the proper shaped forward extending projections on the pressure plate in lieu of a single cylindrical rod. Moreover, the generator will function satisfactorily without any internal perforation. Compaction pressures of 5,000 to 20,000 pounds per square inch are adequate to form the gas generator grain. An igniter is used to bring the substituted glyoxime to its decomposition temperature. Once decomposition starts, enough heat is produced to make the decomposition self-sustaining. Any igniter presently used to fire the compositions of conventionally fueled gas generators can be used to initiate the substituted glyoxime decomposition. Squibs and hot wires are examples of acceptable firing means.

When a compacted composition lacks adequate structural strength for the particular configuration desired, available uncured liquid organic polymeric binders, such as polybutadiene acrylic acid or carboxyl-terminated polybutadiene (in amounts from about 5% to about 15% by weight) can be used to impart structural integrity for a castable grain. The preferred amount is about by weight. If less than about 5% by weight of liquid polymer is employed, the composition of substituted glyoxime and liquid polymer should be compacted into the hardware as described above. After the polymer is cured, the physical properties of the grain have been altered so that the grain is stronger and more resistant to cracking than a grain lacking the polymeric binder. When about 5% to about by weight of a liquid polymer is incorporated into the substituted glyoxime, the composition may be sufiiciently fluid to pour. If this is the case, the composition is poured into a suitable mold or the fuel chamber itself and allowed to be cured into a solid grain. If the composition is not sufficienlty fluid for pouring, compacting procedures are again necessary.

The incorporation of the polymeric binder does improve the physical properties of the grain. However, since the polymeric material may function as a fuel as well as a binder, it is apparent that the burning of the binder will affect the particle size and content of the exhaust plume. Therefore, when feasible, it is preferable that as little binder as practical be employed if reduction of infrared transmission interference is the major objective, and in such instances, the binder should not exceed about 15 by weight of the composition.

In other embodiments of this invention, a minor proportion of an oxidizer such as ammonium nitrate is provided in the composition. Ammonium nitrate is smokeless and therefore preferred. It is incorporated in the compacted or binder-containing solid at a proportion up to about weight percent. These embodiments allow the use of less expensive material for a portion of the composition Without unduly increasing the particles in the exhaust plume. Higher proportions result in unfavorable burning characteristics.

Various other modifications and variations of this invention will become readily apparent to those skilled in the art in the light of the above teachings, which modifications and variations are within the spirit and scope of this invention.

I claim:

1. A gas generator composition consisting essentially of compacted hydroxyl-, amino-, or halogen-substituted glyoxime in the form of a shaped propellant charge, said substituted glyoxime undergoing self-sustaining decomposition to produce decomposition products after said substituted glyoxime is brought to its decomposition temperature by suitable ignition means.

2. The composition according to claim 1, additionally containing up to about 5 weight percent of a compatible organic polymeric binder.

3. The composition according to claim 1, wherein said glyoxime is 1,2-diaminoglyoxirne.

4. A gas generator composition selected from an hydroxyl-, amino-, or halogen-substituted glyoxime in combination with a suitable organic polymeric binder in a mixture consisting of about 5 to about 15 weight percent of a suitable organic polymeric binder, said binder being compatible with said glyoxime, and the balance of said mixture being said glyoxime, said substituted glyoxime undergoing self-sustaining decomposition to produce decomposition products after said substituted glyoxime is brought to its decomposition temperature by suitable ignition means.

5. The composition of claim 4 wherein said organic polymeric binder is selected from the group consisting of the copolymer of polybutadiene and acrylic acid and carboxyl terminated polybutadiene.

6. A gas generator composition which comprises substantially percent of a mixture of a glyoxime selected from an hydroxyl-, arnino-, or halogen-substituted glyoxime, and ammonium nitrate, said substituted glyoxime undergoing self-sustaining decomposition to produce decomposition products after said substituted glyoxime is brought to its decomposition temperature by suitable ignition means, said ammonium nitrate being provided in said mixture at a proportion up to about 20 weight percent, and wherein said mixture is in the form of a compacted solid shaped propellant charge.

7. A gas generator composition comprising a cured mixture of a glyoxime selected from an hydroxyl-, amino-, or halogen-substituted glyoxime, said substituted glyoxime undergoing self-sustaining decomposition to produce decomposition products after said substituted glyoxime is brought to its decomposition temperature by suitable ignition means, a binder of about 5 to about I15 weight percent, said binder being a suitable organic polymeric binder that is comptatible with said glyoxime, and ammonium nitrate at a proportion up to about 20 weight percent.

8. The composition according to claim 1 wherein said glyoxime is 1,2-dihydroxyglyoxime.

9. The composition according to claim 1 wherein said glyoxime is 1,2-difluoroglyoxime.

10. A gas generator composition consisting essentially of 1,2-diaminoglyoxal dihydrazone, said dihydrazone being in the form of a compacted solid shaped propellant charge, and said dihydrazone undergoing self-sustaining decomposition to produce decomposition products after said dihydrazone is brought to its decomposition temperature by suitable ignition means.

References Cited UNITED STATES PATENTS 2,159,234 5/1939 Taylor 149-46 X 2,455,205 11/1948 Whetstone et a1 149-46 X 2,637,274 5/1953 Taylor et a1 149-46 X 2,904,420 9/1959 Holker 149-46 X 2,977,208 3/1961 Harper et al 149-46 3,046,829 7/1962 Roemer 149--19 X 3,073,730 1/1963 Doe et al. 149--19 3,126,304 3/1964 Penner et al. 149'--19 3,177,101 4/1965 Vriesen 149-60 X 3,214,304 10/1965 Vriesen 149-60 X STEPHEN J. LECHERT, JR., Primary Examiner US. Cl. X.R. 

